Episode 154: Heart Failure and GDMT - a podcast by Rio Bravo Family Medicine Residency Program

Episode 154: Heart Failure and GDMT

Dr. Malave explains the four main medications that are part of the guideline-directed medical therapy of heart failure with reduced ejection fraction. Dr. Arreaza added comments and questions.  

Written by Maria Fernanda Malave, MD. Edits by Hector Arreaza, MD.  

You are listening to Rio Bravo qWeek Podcast, your weekly dose of knowledge brought to you by the Rio Bravo Family Medicine Residency Program from Bakersfield, California, a UCLA-affiliated program sponsored by Clinica Sierra Vista, Let Us Be Your Healthcare Home. This podcast was created for educational purposes only. Visit your primary care provider for additional medical advice.

Brief introduction: Heart failure (HF) is a common condition that affects about 23 million people in the world, and it is estimated that 50% of cases are due to heart failure with reduced ejection fraction (HFrEF). It is a major public health concern because of the high morbidity and mortality with a 5-year survival rate of 25% after hospitalization due to HFrEF.

In recent years, the management of HFrEF has evolved due to increased evidence in favor of certain medications. Guideline-directed medical therapy (GDMT) is the foundation of medical therapy for these patients, and it is the result of multiple randomized controlled trials and reviews favoring four main drug classes: 1. renin-angiotensin system inhibitors (angiotensin-converting enzyme inhibitors -ACEi- and angiotensin receptor blockers -ARB), 2. evidence-based β-blockers, 3. mineralocorticoid inhibitors, and 4. sodium-glucose cotransporter 2 inhibitors -SGLT-2i-. 

The benefit of this therapy is mostly seen when these four groups of medications are used in conjunction. During this episode, we will provide some key elements about the prescription of these medications, but this is only an overview, and you are invited to continue learning from reputable sources.

Definitions: HF is defined as the impairment of the heart to meet the metabolic demands of the body. It can be caused by multiple conditions that interfere with the filling up of the heart or conditions that prevent an effective ejection of blood out of the heart. 

Classification of HFrEF: Based on the EF by echocardiogram, heart failure can be classified as:

1. Heart failure with preserved ejection fraction (HFpEF) when the EF is 50% or more.
2. Heart failure with mildly reduced ejection fraction when EF ranges between 41-49%.
3. Heart failure with reduced ejection fraction (HFrEF) when EF is 40% or less.

GDMT: Once we make the diagnosis of HF, it is key to educate our patients and re-educate them every single visit about the importance of guideline-directed medical therapy (GDMT) and lifestyle modifications, because this can change the prognosis and exacerbation rates. Many patients think that since they are feeling well after starting GDMT they can stop it, but that’s going to increase exacerbations, hospitalizations, and decrease quality of life. 

Key points to discuss with patients.

First, discuss that GDMT are disease-modifying drugs that regulate the neurohormonal system to stop the progression of the disease. We should explain to our patients that medications should be taken despite feeling well. Also, patients should be educated about regular follow-ups and medication titration. We can even instruct our patients about increasing their furosemide dose if they observe signs of overload, such as a weight increase of 2-3 kgs in 3-4 days, tight rings, socks or bracelets, also Paroxysmal nocturnal dyspnea, dyspnea on exertion, and more.  

Second, lifestyle modifications such as: quit smoking and alcohol. Additionally, in general, water restriction between 1.2-1.5L daily, salt restriction (there is no official recommendation about how many grams, but in general we recommend less than 2g daily). 

Third, it is highly recommended to do aerobic exercise that produces mild dyspnea since this improves cardiovascular capacity and decreases hospitalization risk. 

Patients should be encouraged to have their annual influenza vaccine and pneumococcal vaccine according to their own immunization schedule. According to the AFP journal, in September 2022, researchers found a clinically and statistically significant reduction in all-cause mortality for patients who received an influenza vaccine right after an MI, with a number needed to treat of 50, the effectivity of the vaccine may vary by season.

GDMT, groups of medications:

What are the basic medications any patient with HF should be on? At least, patients should be on angiotensin receptor blockers ARBs/ACEIs and Beta-blockers. Let’s keep in mind that beta-blockers should be given cautiously in cases of exacerbation, but in general low doses are safe. 

We also have the angiotensin receptor/neprilysin inhibitors (ARNIs), a group of medications whose representative is the combination of sacubitril/valsartan, aka Entresto®. This medication should be the target once ARBs/ACEIs are tolerated. ARBs/ACEIs/ARNIs should be discontinued in the setting of advanced CKD, with a GFR of 30 or less. 

This applies to other medications used in HF such as SGLT-2 and mineralocorticoid receptor antagonist (MRA, such as spironolactone/eplerenone). 

Remember that SGLT-2 inhibitors should be started regardless diabetes status, and BB are safe in the setting of CKD. 

We also have other groups that are considered safe in patients with advanced CKD such as hydralazine/isosorbide dinitrate (combined or not), which are used in African Americans whose BP and HF symptoms do not improve with maximally tolerated dose of ARBs/ACEIs + BB.

Ivabradine: Let’s not forget about ivabradine, which is an SA node inhibitor like BB. Patients need to meet criteria such as a maximally tolerated dose of beta-blocker, heart rate of a least 70 or more and being on normal sinus rhythm to be started on this medication. 

Ivabradine does not improve survival as BB do, so even though they are not contraindicated in HF exacerbation, BB are still preferred since ivabradine does not decrease mortality.

Titration and follow-ups in the HF management:

-ARBs/ACEIs/ARNIs should be titrated approx. Q2 weeks until the maximally tolerated dose is achieved, ARNI should be titrated up Q2-4weeks. With these medications, we should monitor BP, potassium levels and Glomerular Filtration Rate (GFR). 

-BB can also be titrated up Q2weeks until the maximally tolerated dose is achieved. HR, BP and signs of congestion should be observed in patients on BB. Same for hydralazine/isosorbide, with BP follow-up. 

-MRA, such as spironolactone/eplerenone, these meds can be added in patients who remain symptomatic despite maximally tolerated doses of “ARBs or ACEIs or ARNIs” plus Beta-blockers. For MRA, potassium level, and GFR should be monitored every 2-3 days after initiation, 7 days after titration, monthly for 3 months, and then Q3 months. To start a patient on MRA, K+ must be lower than 5.

Patients with HF should be followed up at least in a 2-week interval either via telephone, telemedicine, or clinic visit to assess symptoms, vital signs, bloodwork and to perform a physical exam. 

Monitoring EF: After 3-6 months of the patient´s stabilization, we should reorder an echo, EKG, BNP and Basic Metabolic Panel. The ejection fraction improves in all patients after GDMT initiation and compliance, and in some patients, this improvement is very significant, so we need to reassess EF after stabilization. 

Comorbidities: Also, let´s keep in mind that most of the patients have associated comorbidities such as Afib, diabetes, valve disease, or anemia. These comorbidities must be addressed either by starting anticoagulation, adjusting anti-diabetes medications, starting iron, or referring to cardiology if a valve replacement is needed.

When to refer to Cardiology? 

Some patients will qualify for device therapy (ICD) as a primary prevention for ventricular arrhythmias that can degenerate either into torsades or ventricular fibrillation. These patients must be symptomatic, at least in 3 months of maximally tolerated GDMT, and EF between 30-35%. Symptomatic <35%, asymptomatic <30%. Other patients will require ICD implantation for secondary prevention. 

Other criteria to refer a patient to the cardiologist are: patients resistant to GDMT despite target or maximally tolerated doses, or with worsening symptoms, two or more hospitalizations in 12mo, low blood pressure, tachycardia, and end-organ failure. 

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Conclusion: Now we conclude episode number 154, “Heart Failure and GDMT.” Remember that GDMT can improve not only the symptoms of heart failure with reduced ejection fraction, but it can also improve mortality. The four main classes of medications are renin-angiotensin system inhibitors, beta-blockers, mineralocorticoid inhibitors, and SGLT-2 inhibitors.

This week we thank Hector Arreaza and Maria Fernanda Malave. Audio editing by Adrianne Silva.

Even without trying, every night you go to bed a little wiser. Thanks for listening to Rio Bravo qWeek Podcast. We want to hear from you, send us an email at RioBravoqWeek@clinicasierravista.org, or visit our website riobravofmrp.org/qweek. See you next week! 

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References:

1. Murphy SP, Ibrahim NE, Januzzi JL Jr. Heart Failure With Reduced Ejection Fraction: A Review [published correction appears in JAMA. 2020 Nov 24;324(20):2107]. JAMA. 2020;324(5):488-504. doi:10.1001/jama.2020.10262. Link: https://pubmed.ncbi.nlm.nih.gov/32749493/
2. Patel J, Rassekh N, Fonarow GC, et al. Guideline-Directed Medical Therapy for the Treatment of Heart Failure with Reduced Ejection Fraction. Drugs. 2023;83(9):747-759. doi:10.1007/s40265-023-01887-4. Link: https://pubmed.ncbi.nlm.nih.gov/37254024/
3. Royalty-free music used for this episode: Latin Chill, downloaded on July 20, 2023, from https://www.videvo.net/.

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